Social support is an important but frequently under-examined factor in smoking cessation. Specifically, social support has been found to play a key role in successful smoking quit attempts, but efforts to add a social support component to interventions targeting the smoker have not been effective. Thus, a challenge is how to optimize the role of social support in smoking cessation. Moreover, for greatest impact, smoking interventions need to reach as many cigarette smokers as possible. Directly recruiting and intervening with support persons as change agents for smoking cessation represents a shift from conventional interventions that focus almost exclusively on the smoker. As a first step, a validated measurement tool is needed for the quantification and characterization of support behaviors that assist a smoker's effort to quit smoking. Existing measures of support for smoking cessation have been primarily designed to address supportive behaviors received and reported by the smoker. No previous measure has been developed for completion by a support person to assess smoking-specific support behaviors provided by a support person, to a smoker. The current proposal builds on our previous work where we developed and obtained preliminary data on the Support Provided Measure, a self-report questionnaire designed to assess smoking-specific support behaviors provided by a support person to a smoker. This study will enroll a random sample of smoking patients seen at the Mayo Clinic to assess the validity and test-retest reliability of the Support Provided Measure and a complementary measure of social support received for smoking cessation, the Support Received Measure, designed to be completed by a cigarette smoker. A random sample of married, adult, Mayo Clinic patients seen for any medical appointment in the previous 12-month period, with current cigarette smoking indicated in their medical record, will be mailed a survey packet of questionnaires designed to be completed by the identified smoker and their spouse. The goal is to obtain responses from 400 smoker/spouse pairs. Two weeks following receipt of the initial completed survey packet, a random sample of those returning the initial mailed questionnaires (goal of 60 smoker/spouse pairs) will be sent a second survey packet (Support Provided and Support Received Measures only) to determine the test-retest reliability of these two measures. The primary aims of this study are 1) to assess the concurrent validity of the Support Provided Measure and the Support Received Measure; 2) to determine the factor structure of both measures; and 3) to assess the test-retest reliability of the measures over a 2-week period. Secondary aims are to assess the degree of association between the Support Provided and Support Received Measures and to examine the association of smoker and spouse demographic and psychosocial characteristics and tobacco-use variables with initial scores on both measures. In future studies, we will extend measurement of supportive behaviors provided to non-spouses. The availability of validated measures of support provided and received will facilitate intervention development and will allow the assessment of support as a covariate in smoking cessation intervention trials. Results of this study will serve as a building block for future NIH submissions examining social support and smoking cessation.